Hair sprays provide human hair with a particular shape or configuration and function by applying a thin film of a resin or gum onto the hair to adhere adjacent hairs together so that they retain the particular shape or configuration at the time of application. Many of these hair sprays have been applied from aerosol compositions that include a liquefiable propellant gas - generally a halohydrocarbon, such as trichlorofluoromethane or trichlorotrifluoroethane or a gaseous hydrocarbon such as propane or butane. Recently proposed legislation, directed to the depletion of the atmospheric ozone layer has led to the halohydrocarbons being increasingly replaced with pure gaseous non-halogenated hydrocarbons as propellants. However, the use of non-halogenated hydrocarbons as propellants has resulted in a problem of decreased solubility of the hair spray resin or gum in water requiring an increased amount of volatile organic solvent, such as ethanol, to achieve sufficient solubility, therefore creating an additional ecological problem.
As set forth in the Nuber, et al. U.S. Pat. No. 4,767,613, a film-forming terpolymer of vinylpyrrolidone, t-butyl methacrylate and methacrylic acid monomers can be at least partially neutralized to improve the water solubility or dispersibility of the resin and provide the resin with the quality of being easier to remove from the hair during washing. However, as disclosed in the Nuber, et al. U.S. Pat. No. 4,767,613, such aerosol hair treating agents generally have a maximum of about 5% water and require a high amount, up to about 95% by weight, of a volatile organic solvent, such as alcohol, despite the increased solubility of the neutralized resin.
As stated in the product literature of Stepan Company, of Northfield, Ill., directed to the use of the terpolymer of vinylpyrrolidone/ethyl methacrylate/methacrylic acid (STEPANHOLD EXTRA) for use as a fixative hair spray, this particular fixative polymer was designed specifically for pump sprays, not aerosol hair sprays. The terpolymer apparently was not found to be compatible with hydrocarbon propellants, or required far too much alcohol solvent to satisfy volatile organic contaminant regulations. Surprisingly, in accordance with the present invention, it has been found that excellent and homogeneous delivery of the terpolymer can be achieved with the use of dimethyl ether as the propellant.
Stepan Company discloses one example of an aerosol hair spray that includes the terpolymer of the composition of the present invention and has 41.10% by weight water, but the composition also includes 45.70% by weight alcohol, as follows, where percentages are percent by weight: Terpolymer of polyvinylpyrrolidone, ethyl methacylate, and methacrylic acid 9.60%; SDA 40 Alcohol (190 Proof) 45.70%; AMP (Regular) 0.40%; Silicone L-722 (Union Carbide) 0.50%; Propylene Glycol 2.00%; Perfume V-5177 (Van Dyke) 0.60%; 54 Morpholine in SDA 40 Alcohol 0.10%; and Distilled Water 41.10%.
In accordance with the present invention, a new and improved aerosol hair spray styling aid composition has been found wherein a terpolymer of vinylpyrrolidone/ethyl methacrylate/methacrylic acid --at least partially neutralized for water solubility; and about 25% to about 50% dimethyl ether propellant, particularly at least about 25%, to about 40% by weight dimethyl ether propellant and preferably about 25% to about 35% by weight dimethyl ether propellant; can be suitably solubilized or dispersed in the aerosol composition containing about 30% to about 80% water and less than 40% volatile organic compounds (such as alcohol solvents and/or propellants), particularly less than about 35% volatile organic compounds (excluding the propellant), e.g., 0-30% ethanol, preferably 5-25% alcohol, while providing an aerosol spray styling aid that can effectively solubilize or disperse from about 1% to about 12%, by weight of the composition, of the terpolymer, more suitably about 2% to about 10% by weight terpolymer, and preferably about 2% to about 8% by weight terpolymer, with a volatile organic compound, e.g., alcohol, being optionally included for fast drying.